Transport and Elimination

National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709 

A dramatic example of how transporters can alter the efficacy and toxicity of a commonly prescribed drug is provided by the following scenario. Three 70-kg males with identical symptoms see a physician and are diagnosed with mild cardiac insufficiency. For all a standard treatment with digoxin, a cardiac glycoside that increases the strength of heart muscle contractions, is recommended and all follow the 

Molecular and Biochemical Toxicology, Fourth Edition, edited by Robert C. Smart and Ernest Hodgson Copyright 2008 John Wiley Sons, Inc. 

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Disease can be a major factor in reducing the body s ability to rid itself of xenobiotics. Liver, kidney, and cardiovascular disease can impair the ability to metabolize, transport, and eliminate toxic chemicals. 

Thus, red blood cell carbonic anhydrase which catalyzes the reversible hydration of CO2, plays a vital role in carbon dioxide transport and elimination. Carbonic anhydrase is a monomeric (M.W. 29,000) zinc metalloenzyme and is... 

Krewson CE, Saltzman WM. Transport and elimination of recombinant human NGF during long-term delivery to the brain. Brain Res 1996 727 169-181. 

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